Automatic multiple cycle apparatus for machine tools



March 3 1953 T. B. BUELL ETAL AUTOMATIC MULTIPLE CYCLE APPARATUS FOR MACHINE TOOLS Filed Oct. 7, 1948 7 Sheets-Sheet 1 fig 0e Zara.- 5177 Z fijaer,

Q I m March 3, 1953 T. B. BUELL ET AL AUTOMATIC MULTIPLE CYCLE APPARATUS FOR MACHINE TOOLS Filed Oct. 7, 1948 7 Sheets-Sheet 2 m R a mm mm, w w: m w W mm fZ/ m? mm wm F Z m %m m m m 2m 2m m a 6 m V j m mm 5 Q mm {E m u W nu iv 1. P W I l mmm lmn m w H m .VWNQ m r wm m m z W 5? m Q w Q MN m MN m n Q; i km March 3, 1953 'r. B. BUELL ET AL 2,630,038

AUTOMATIC MULTIPLE CYCLE APPARATUS FOR MACHINE TOOLS Filed Oct. 7, 1948 7 Sheets-Sheet 3 L/ L2 L mac f (5% 052 2 06 E Z We M55 fi s 20/5 R/I/ 7'6 9r! 20/6 TRG 6 20/4 rm 7 2 March 3, 1953 T. B. BUELL ET AL 9 AUTOMATIC MULTIPLE CYCLE APPARATUS FQR MACHINE TOOLS Filed Oct. 7, 1948 7 Sheets-Sheet 5 m m 44ml, g

AUTOMATIC MULTIPLE CYCLE APPARATUS FOR MACHINE TOOLS Filed Oct. '7, 1948 7 Sheets-Sheet 6 emi r's 12771014 Eluel jzar'fy F. Label Patented Mar. 3, 1953 AUTOMATIC MULTIPLE CYCLE APPARATUS FOR MACHINE TOOLS Timothy B. Buell and Harry R. Leber, Rockford, Ill., assignors to Sundstrand Machine Tool (30., Rockford, 111., a corporation of Illinois Application October 7, 1948, Serial No. 53,192

15 Claims.

The invention relates to manufacturing lathes and the provision of mechanism therein for automatically repeating cyclic movements of tools to remove two or more layers of material from a work piece with a single setting of the machine. It is the general object of the invention to provide a new and improved lathe of this character.

Another object is to provide a lathe having front and rear carriages movable longitudinally of the work spindle axis and front and rear tool supporting cross slides carried upon said carriages respectively, means for actuating said front carriage and slide to advance tools thereon to the work and then perform a turning operation during which the tools move longitudinally of the work axis, after which the tools are withdrawn from the work and returned to their starting position, means for moving the rear slide towards and from the work axis to cause tools thereon to perform a facing operation, means for adjusting the tools on the cross slides to change the depth of cut thereof, and means for controlling said slide actuating means to effect said movements and to repeat the movements automatically for a second cut with the tools adjusted to a new depth of out.

Other objects and advantages will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary plan view of a lathe embodying a preferred form of the invention;

Fig. 2 is a transverse section approximately along the line 2-2 of Fig. 1;

Fig. 3 is a diagrammatic view of the gearing for actuating the work and tool supports;

Figs. 4 and 5 comprise together a wiring diagram of electrical circuits; and

Fig. 6 is a fragmentary detail view of a portion of the mechanical control mechanism; and

Figs. 7, 8 and 9 comprise together another type of wiring diagram substantially equivalent to Figs. 4 and 5, but with parts of the starting and braking circuits omitted for simplicity.

While we have shown in the drawings and shall herein describe in detail a preferred form of the invention, it is not intended to limit the invention to the particular form and arrangement shown. The scope of the invention will be pointed out in the appended claims.

In the drawings, the invention is embodied in a lathe having a bed 20, a work spindle 2| rotatably mounted in a head stock 22 and carrying a work piece W, a front carriage 23 slidably supported on the bed for movement longitudinally of the work spindle, a front tool cross slide 24 movable transversely on the front carriage and adapted to support one or more turning tools 25, a rear carriage 26 adjustably supported on the bed for movement longitudinally of the work spindle, and a rear tool cross slide 21 movable transversely on the rear carriage and adapted to support one or more facing tools 28.

The actuating mechanisms for the work supporting spindle 2| and the tool supports are shown somewhat diagrammatically in Figs. 1 to 3 and are generally of the type disclosed in U. S. Letters Patent No. 2,144,735 dated January 24, 1939, to Granberg et al. which discloses a lathe of the type wherein the present invention is embodied. The spindle 2| is driven by a motor 30 by means including a belt drive 3|, a shaft 32, pick-01f gears 33, a shaft 34, a pinion 35, and gear 36. The actuating mechanisms for the carriages and cross slides are adapted to actuate said tool supports at feed and rapid traverse rates. The feed drive comprises gearing connected to the spindle 2| and includes a gear 40 on the spindle, a train of gears 4|, a second train of gears 42, a shaft 43, pick-off gears 44, a shaft 45, gears 46, a planetary gear device having a ring gear 41 on a planet carrier, three sets of planetary gears 48 rotatably supported equidistantly apart on said carrier, a sun gear 49 on shaft 56, pinion 5| also on shaft 50, and a gear train 52 to a front carriage feed screw 53 having screw threads 54 therein engageable with a nut 55 on the front carriage 23.

For driving the front carriage at a traverse rate, the left hand planet gears 48 engage a second sun gear 56 on a shaft 51 which has a pulley 58 connected by a belt 59, and a pulley 60 on the shaft 6| of a reversible rapid traverse motor 62. An electric solenoid brake 63 is associated with the other end of the motor shaft 6| and is operable when deenergized to hold the motor shaft against rotation and thereby hold the sun gear 56 stationary. When the traverse motor 62 is operated the drive therefrom to the planetary gearing is superimposed upon the drive through said gearing from spindle 2| so as to operate shaft 50 at a relatively higher rate in a forward or reverse direction depending upon the direction of the rotation of the traverse motor. A shaft 64 carrying the intermediate gear of the train 52 also has a worm 65 thereon meshing with a worm wheel 66 on a shaft 6'! carrying a control drum 68 having dogs which actuate a drum switch 330 through the medium of an actuating arm 338. I

For actuating the rear cross slide 21, a gear train 69 drives a shaft "l which carries one of two pick-off gears "H the other of which is fixed to a shaft 12 which is splined at l3 and carries a worm 14 which meshes with a worm wheel 15 on a shaft which also carries a cam drum TI. This cam drum has a cam slot with a spiral portion 18 and a dwell portion 19, a roller follower 80 engaging said slot to actuate the rear tool cross slide as hereinafter more fully described.

The control for starting and stopping the spindle motor 38 and for actuating the feed traverse mechanism for the tool supports in order to obtain tool support movements or cycles comprising a rapid advance movement of the tool supports to bring the tool into proximity with the work, followed by a feed movement of the tool supports during the cutting operations and thereafter by a rapid traverse return movement of the supports to return the tools to their initial withdrawn positions is described in said uranoerg et a1. Patent No. 2,144,735.

The front cross siioe 24 is formed with a bore 84 extending transversely of the axis of the work spindle 2|. A cylindrical member 85 is slidably mounted in the bore 84 and carries a cam follower roller 86 extending downwardly therefrom into engagement with a cam slot 81 in a cam bar 88. The cam bar is stationarily mounted on the bed of the lathe by means including a bracket 89. As shown in Fig. l, the cam slot has a portion 8m parallel to the spindle axis, a diagonal portion 81b, and a portion 810 also parallel to the spindle axis. When the cylindrical member 85 is held fixed in the bore 84 the cam follower 86 engages in the slot 81 to move the cross slide transversely of the carriage and towards the spindle axis as the carriage moves longitudinally towards the head stock to carry the follower 86 from the cam slot portion 81a through the portion 811) and into the portion 810. During this movement of the cross slide and carriage the tools are moved from a withdrawn position diagonally towards the position wherein the cutting operation is started and thereafter during continued movement of the carriage towards the head stock the follower 86 moves in the cam slot portion 810 to maintain the cross slide at its point of farthest advance while the tools perform a turning operation on the work piece W. Upon completion of the turning operation, the carriage drive is reversed to return the carriage at a rapid traverse rate and the tools are retracted first parallel to the work and then diagonally away from the work as the follower 88 passes first along the cam slot portion 810 and thereafter through portion 812) towards or into portion 81a. The follower 86 is at all times maintained in contact with the left hand side of the slot 81 as shown in Figs. 1 and 2 by means of a coil compression spring 89 located intermediate a depending bracket 8I on the cross slide and a collar 82 carried on a rod 83 secured to the carriage 23.

The cylindrical member 85 is adjustable in the bore 84 of the cross slide in order to determine the extent to which the cross slide will be moved toward the spindle axis and thereby determine the depth of cut of the turning tools 25. As shown in the drawings, the member 85 has a central bore 90 and a nut 9| secured in one end thereof. A feed screw 92 engages the nut 9! and also carries a Worm wheel 93 which meshes with a worm 94 carried on a shaft 95 of a reversible electric motor 96. A bevel gear 91 on the shaft 95 meshes with a corresponding bevel gear 98 on a shaft 99 which is squared at its outer end I00 to receive a crank to facilitate manual adjust- 4 ment of the cross slide with respect to the member 85. The manual adjusting means is generally utilized for initial setting up of the lathe and determining the depth of the cut of the turning tools 25 on the first roughing out. When it is desired to take two or more successive cuts automatically on the work piece, the second adjustments for the second and third cuts are preferably obtained by use of the motor 96 and control hereinafter more fully described. As illustrated in figs. 1 and 2, the control includes limit switches ILS, 2L8 and 3L8 supported on the cross slide 24 and arranged to be actuated by switch actuating members I05 extending radially from a disk lutia on the upper end of a shalt luli which is rotatably supported in a vertical bore I81 in the cross slide and at its lower end carries a pinion I88 which meshes with rack teeth ")9 on the adjacent side of the cylindrical member 85.

The rear tool cross slide 21 is ad ustable transversely of the rear carriage 26 and of the spindle axis by mechanism generally the same as that just described with respect to the front tool cross slide. 'lhus, the rear slide 21 has a bore H8 in which a cylindrical member l'l' l is adjustable. This cylindrical member has a central bore l l2 and has a nut at the right hand end thereof which is engaged by a feed screw H4 which also carries a worm wheel H5. The worm wheel engages a worm [IE on a shaft ll! of a reversible electric motor H8. A bevel gear H9 is secured on shaft ill and meshes with a bevel gear I20 on a shaft iii which is squared at its outer end I22 to receive a manually operable crank. The cylindrical member Ill carries the cam follower roller 88 hereinbefore referred to and also has rack teeth I23 thereon which engage a pinion I24 on the lower end of a vertical shaft I25 which is rotatably supported in the cross slide 21 and which at its upper end carries switch actuating members [26 extending radially from a disk I21. Switches 4L3 and 5LS are supported on the cross slide adjacent the switch actuating members so as to be actuated thereby.

Normally, the rear carriage 26 is adjusted longitudinally of the bed 20 by suitable means (not shown) to a desired location so that when the cross slide 21 is moved transversely of the work spindle axis during operation of the machine the facing tools 28 will perform facing operations on the work piece W at the desired points longitudinally of the work piece. These facing operations are generally used to clean out the end of the cuts formed by the turning tools and generally the facing tools are moved inwardly so as to reach their final positions simultaneously with or after the completion of the turning operations.

In the preferred form of the invention illustrated herein, the tool supports are preferably moved to provide a series of two or three turning operations and two facing operations with a single starting of the machine, each turning operation reducing the diameter of the work piece.

The limit switch ILS is closed by the operating member I at the beginning of each cycle of carriage operation and is opened when the front slide completes each adjusting movement; limit switch 'ZLS is closed at the end of the first front slide adjustin movement; and limit switch 3LS is closed at the end of the second front slide adjusting movement. Limit switch iLS is similar to lLS except that it is operated by movements of the rear slide, and limit switch 5LS closes at the end of the rear slideadjusting movement.

The electrical control for obtaining cyclic 'operation of the machine is illustrated principally in the schematic diagram of Figs. 4 and 5, and 7-9, wherein. the control system as disclosed comprises power circuits and control circuits, the latter including the control drum switch 338 actuated by dogs on the drum controller 68. The electrical circuits will be described with reference to Figs. 4 and 5. Equivalent circuits are shown in Figs. 7-9, except for certain portions which have been omitted for simplicity.

PO'WER CIRCUITS Line wires Ll, L2 and L3 comprise the three lines of a three phase alternating current supply, and the motors which operate the machine are connected across these lines through switching a rangements as will be described. The rapid traverse motor 62 is arranged for connection to said current supply alternatively through a rapid approach switch device having contacts RA or through a rapid return switch device having contacts RR, this alternative arrangement providing a means for reversing the motor to provide advance movement of the front carriage 23 and return movement thereof.

The motor 96 which drives the front cross slide similarly is arranged for connection to the supply alternatively through a front slide approach switch device having contacts FSA or through a front slide return switch device having contacts FSR, this arrangement again providing for reverse operation of the motor. The motor 96 is preferably provided with a spring applied brake oi well known construction within a housing designated at 95a in Fig. 1, which housing also contains a plugging arrangement including a witch shown schematically at FPS in Fig. 5 and having associated therewith conventional apparatus for opening the switch in response to stopping (or near stopping) of rotation of the motor 95. The brake is released electrically by means including a coil FSB (shown in Fig. 4 only) connected across the motor 96 and arranged to release the brake when said motor is energized.

The motor H8 for driving the rear cross slide is similarly arranged to be connected alternatively to the supply line through a rear slide approach switch device having contacts RSA or through a rear slide return switch device having contacts RSR. Similarly, this motor has a brake within the housing designated at 8a in Fig. 1 and operable by a solenoid coil RSB (shown in Fig. 4 only) which is connected across the motor. Another plugging switch ZPS and associated apparatus is within the housing l I812.

A coolant motor I30 which is provided to drive a pump for circulating coolant through the machine is also arranged to be connected across the line through a switch device having contacts CS. The contacts RA, RR, FSA, FSR, RSA, RSR and CS are electromagnetically operated, these contacts respectively being associated with relay devices, the operating coils of which are in the control portion of the circuit as will :be hereinafter described.

The spindle motor 30 is adapted to be connected across the supply line through a switch device having contacts MR. Because of the size of the spindle motor we preferably provide an automatic starting device comp-rising a transformer T5 which is connected in parallel with the contacts MR through the contacts MS on the line side and the contacts MS on the motor side. This transformer arrangement is utilized for starting the motor, after which the motor is shifted into direct connection with the line through the contacts MR. This starting arrangement has been omitted from Fig. '7 for simplicity, and in Fig. '7 the spindle motor 30 is shown as being started directly across the line.

It will be seen that while the motors E2, 96, I I8 and I30 are started directly across the line, in Fig. 4 the spindle motor 39 is started by a reduced voltage arrangement from the transformer T5 and consequently requires a separate starting circuit. This starting circuit comprises an operating coil MSC which controls the contacts MS and MS and a normally closed switch M83, an operating coil MRC which controls the contacts MR, and a timer device including an operating coil TRC, a timer motor TM and normally closed timer relay switches TR! and TR2 and a normally open timer relay switch TR3. The coils MSG, MRC and TRC are connected generally in parallel, one side of each of said coils being connected to one line wire by means of a lead Zilll and the other side of said coils being connected to another line wire by means of a lead 2M which incorporates a normally open switch i5CR3.

In Fig. 4a branch lead 20la connects one side of the switch |5CR3 to the coil MSC and incorporates the normally closed timer switch TRI; a second branch lead 20lb connects said switch to the coil MRC and incorporates in series the normally open timer switch TR3 and the normally closed switch M83 associated with the starting relay coil MSC; a third branch lead 20IC connects the switch I5CR3 directly to the coil TRC; and a fourth branch lead Zilld is connected between the lead ZRHC and the coil TRC, the lead Zilld incorporating in series the timer motor TM and the normally closed switch TR2.

It will be seen that with this starting arrangement when the switch l5CR3 (which is controlled by an operating coil in the control portion of the circuit) is closed the coil MSC is energized, closing the contacts MS and MS to start the motor through the low voltage transformer T5, while the switch MS3 in series with the coil MRC is opened. Additionally, closure of the switch I5CR3 energizes the timer coil TRC and timer motor TM, and after a predetermined lapse of time this motor operates the timer to cause the switches 'I'Rl and TR2 to open and the switch TR3 to close. Switch TRI breaks the circuit to the coil MSC, cutting out the transformer T5 while closure of the switch TR3 (and simultaneous closing of switch MS3 when coil M50 is deenergized) makes the circuit to the coil MRC, and energization of this coil closes the contacts MR and connects the motor directly to the line. The timer motor is no longer energized because the switch TR2 is now open.

CONTROL CIRCUITS The control circuits as shown are adapted to provide a two out cycle or a three out cycle of machine operation. A cycle switch CYS (see Fig. 5) is arranged to select the cycle desired. When this switch is set for a two out cycle as shown, the machine runs through two outs before stopping. At the end of the first cut the front and rear cross slides both advance to the next position before the cycle resumes. At the end of the cycle they both return to their original posiion.

For the three out cycle the front cross slide advances one position for each cut and returns to its original position after the third cut. The rear cross slide feeds to the same depth for the first two cuts and advances for a deeper out be- 7 tween the second and third cuts, returning to its original position after the third out.

For supplying control current a transformer T is provided, said transformer having its primary P connected across supply lines Li and L3, a lead 202 connecting one end of said primary to the line wire L3 and a lead 293 connecting the other end of said primary to the line Ll. The secondary S of the transformer is connected to control supply lines CSi and CS2, one of these lines (CS2 as illustrated) being grounded if so desired.

A- brake is provided for the rapid motor 62, this brake being of conventional construction and being designated at 53 in Fig. 3. The brake is operated by a solenoid release coil BRI, this coil being adapted to be energized with direct current obtained from a rectifying device Ri of well known construction. The input to the rectifying device is connected across the secondary of a transformer T2. One end of the primary of this transformer is connected to the control lead CS2 by means of a lead 283% and the other end of the primary is connected to the control supply lead CS1 by a lead 294 incorpora ing series connected normally closed relay switch RRI which is associated with the relay which controls operation of the motor 62 in reverse direction and normally closed relay switch RA! which is associated with the relay which controls operation of the motor 62 in advance direction. When both switches RA! and RRl are closed the coil BRi is energized and the brake is set, and whenever either switch is open the brake is released. The coil BRZ of a solenoid brake 39a for the spindle motor is similarly energized. by direct current from a rectifier R2 having its input terminals connected across the secondary of a transformer T3. One end of the primary of this transformer is connected to the lead CS2 and the other end is connected to lead CSI by a lead 265 which incorporates a normally closed relay switch iZCRI.

The spindle motor drives through a magnetic clutch having an operating coil SC which receives DC energization from a rectifier R3. The

' circuit connecting one end of the coil SC to the rectifier has a resistor 28B incorporated therein,

and a normally open timer relay switch Zi'IRl connected across the resistor. The input terminals of the rectifier are connected across the secondary of a. transformer T4, one end of the "primary of this transformer being connected to the lead CS2 and the other end being connected to the control lead CS1 by a lead 28'! which incorporates a normally open relay switch IZCRZ. When the switches iZCRi and I2CR2 are in the positions shown the spindle brake is set and the clutch between the spindle and the spindle motor is disengaged. When the switches are operated so that lZCRI is opened and IZCRI! is closed the coil BB2 is deenergized to release the spindle brake and the clutch solenoid SC is energized to cause the clutch to engage. When the clutch first engages as the circuit is first closed a portion of the voltage output of the rectifier R3 is developed across the resistor 206, reducing the current through the operating coil SC, and the clutch is caused to pick up smoothly. The operating'coil 2TRC of the timer relay is connected in a lead 208 which extends from the lead "20'! to the control lead CS2 so that this coil is energized when the switch i2CIFt2 is closed. When the relay times out, switch ZTRI associated therewith closes, shorting out the resistor 206 and reducingthe resistance in the circuit 'in-,

cluding the coil SC so that the current through the coil SC is increased and the clutch is engaged with full force.

The control circuit also includes the operatin coil I5CR of a starting relay for the spindle motor 30. This relay has associated therewith three normally open switches IECRI, I5CR2 and I5CR3, the latter of these switches being in the lead 20! in the spindle motor starting circuit as earlier described. The coil I5CR is connected in a lead 2H1 which extends between the control leads CSI and CS2, the lead 2H] incorporating in series with the coil a thermal overload switch 2Il operable as a function of current fiow through overload devices 2| Ia which are in series with the spindle motor; a thermal overload switch 212 operable as a function of current flow through any of overload devices 2|2a, 2|2b, N20 or 212d connected in the circuits of the motors 62, 56, H8 and I30, respectively; and a run normally open push button switch Ml. A lead 213 is connected in parallel with the run switch MI and incorporates in series a normally closed stop push button switch M2 and the normally open relay switch IECRI.

It will be seen from Fig. 4 that closure of the switch Mi will energize the coil IECR, resulting in closure of the switches associated therewith. Closure of the switch IECRI completes a holding circuit around the button Ml so that the coil IECR will remain energized after the button Ml has been released and until the stop switch M2 is opened. Closure of the switch ISCRS will energize the starting circuit for the spindle motor in the manner above described, this motor being energized first through the contacts MS and MS and the reduced voltage transformer T5, and after the time delay provided by the relay TR the spindle motor is switched directly across the line through the contacts MR. It will also be seen that in the event of an overload on any of the motors one of the switches 2 or 2|2 will open and the spindle motor will stop.

The rapid traverse motor 62 which controls traverse movement of the front carriage 23 is energized for movement in a forward direction by closure of the contacts RA. This is accomplished by energizing a relay coil RAC which controls these contacts and also controls'the switch RA] in the rapid motor brake circuit and a normally open switch RA2. The coil RAC is connected in a lead 214 which extends between the control leads CSI and CS2 and which incorporates in series two normally open contacts of a cycle start push button PBI, two normally closed contacts of a jog approach push button P132, a normally closed push button PBS, two normally closed contacts of a cycle top push button PB4, two normally closed contacts of an emergency return" push button P135, a mechanically operated switch comprising a pair of contacts DR-l on a drum control switch 330, a normally closed pair of contacts of a clamp-uncl-amp push button switch M3, and contacts I5CR2 which are closed when the coil R is energized to start the spindle motor, thus providing an interlock between the spindle motor and the forward operation of the rapid traverse motor.

The drum control switch 330 which is mechanically operated by means of 'dogs during the machine cycle and is similar tothe switch disclosed in the above mentioned Granberg application, comprises five switches, DB1, DB2, DB3, DB4 and DB shown in Fig. 4. The drum control switch has three positions: a feed or neutral position wherein switches DBI, DB2, DB3 and DB4 are open and switch DB5 is closed; a rapid approach position wherein switches DBl, DB2 and DB5 are closed and switches DB3, DB4 are open; and a rapid return position wherein switches DBI, DB2 and DB5 are open and switches DB3 and DB4 are closed.

The mechanical operation of the drum switch is shown and described in detail in Granberg et al., Patent No. 2,144,735. Briefly, in addition to the switches shown diagrammatically in Fig. 4 the switch comprises a control or actuating mechanism shown in Fig. 6. As explained in detail in the above mentioned patent, the drum switch is operated by rocking a shaft between three positions to obtain the switch action above described. The means for rocking the shaft automatically in timed relation to the movement of the front carriage 23 comprises dogs on the drum controller 68 which is fixed on the end of the shaft 61 extending parallel with the shaft of the drum switch, the shaft 61 being connected to the drive for the front carriage as shown in Fig. 3. Adiustably mounted on the periphery of the controller disc 68 (which may be graduated to facilitate the spacing) are dogs 334, 335 and 336. Disposed to be acted upon by the dogs during the rotation of the dis-c 68 is a pin 33'! proiecting from an arm 333 which is fixed to the rockable shaft of the drum switch. The dog 334 has a cam surface 334' which engages the pin 33'! to rock the shaft from ra id approach to feed or neutral position. Dog 335 has a cam surface 335 which engages the pin 33! to rock the switch from feed to rapid return position, and dog 3% has a cam surface 335 which engages the pin to rock the switch from rapid return to feed or neutral position. Connected between the dog 334 and the dog 335 is an arcuate bar 348 which overlies the pin 33! and prevents rocking of the switch either manually or automatically from feed to rapid approach position while the front carriage 23 is within the limits of feed movement as defined by the spacing of dogs 334 and 335, thereby assuring that neither the work nor the machine will be injured by a sudden thrust of the tool into the work.

From the above description it will be seen that with the coil 5GB energized to close switch l5CB2, and with the drum switch in rapid approach position so that DB! is closed, if the cycle start push button PE! is manually closed and the other push buttons in the lead 2 Hi are closed as shown, the coil BAC is energized, closing the contacts BA to connect the rapid motor 62 across the supply line and opening the switch BA! to release the rapid motor brake 63. A subsidiary circuit generally in parallel with the cycle start push button PB! and having a portion in parallel with the coil BAC includes the relay switch BA2 associated with the coil BAG which forms a holding circuit around the cycle start push button PEI. Another relay operated switch IICBI is connected in parallel with the cycle start push button PB! and the switch BA2, and the point intermediate the switches HCBl, BA2 and the push button PB! provides a connection for a lead 2|5 extending to the control lead CS2 in parallel with the coil BAC and incorporating a normally open switch I2CB3 and a release coil MCB' for a latching relay having associated therewith a normally open switch MCBI and a normally closed switch I4CB2. The point intermediate the switches IICBIBA2 and the cycle start push button FBI is also connected to the lead 2! through a pair of normally open contacts of the jog approach push button P132 by means of a lead 216.

The control circuits for providing the desired cyclic operation of the machine including the automatic provision of a plurality of cuts of different depth include a lead 2|! connected between the control leads CSI and CS2 and incorporating a tail stock air valve solenoid 248, a normally open pair of contacts on the stop push button M3, and a normally open relay switch I3CBl. A lead 22!! is connected to the lead 210 intermediate the push button MI and the overload switch 2I2, and from the lead 220 a branch 'lead 22! connects with the control lead CS2, this branch lead incorporating the switch DB2 on the drum control switch and the operating coil I3CB of a relay having associated therewith the normally open switch |3CR| which is connected in the lead 2 l1, and a normally closed switch l3CB2 which provides an interlock in the emergency return circuit as will be hereinafter described.

Another branch lead 222 extends from the lead 220 to the control lead CS2 and incorporates the switch DB3 of the drum controller and the coil BBC for operating the contacts BB in the circuit of the rapid motor 62 and for controlling the switch BBI in the rapid motor brake circuit. A lead 223 is connected to the lead 2M intermediate the clamp-unclamp push button 2 M3 and the switch DBI, said lead being connected at its other end to the control lead CS2 and incorporating therein in series the switch DB5 on the drum controller, a second set of normally closed contacts PBS of the emergency return push button, two normally closed contacts of a jog return push button PBS, a second set of normally closed contacts PB4 of the cycle stop push button PB4, a normally closed jog spindle push button PBI, a second set of normally open contacts PB! of the cycle start push button PBI and the operating coil IZCB of a relay having a normally closed switch IZCBI in the circuit of the spindle brake coil BB2 earlier described and three normally open switches I2CB2, I2CB3 and I2CB4, the switch I2CB2 being in the circuit of the spindle clutch solenoid SC as earlier described, and the switch I2CB3 being in series with the release coil MOB as earlier described. The switch I2CB4 is connected in parallel with the switch PBI to form a holding circuit around these contacts of the cycle start push button after the push button is released. Another normally open relay switch IICBZ is connected in parallel with both the switch PB! and the switch l2CB4.

Another lead 224 has one end connected to the lead 2M intermediate the switch |5CB2 and the clamp-unclamp push button M3 and is connected at its other end to the lead 222 intermediate the switch DB3 and the coil BBC, the lead 224 incorporating the normally closed switch I3CB2 and a set of normally open contacts of the jog return push button PBS. A lead 225 connects the normally open switch MCBI across the open contacts of the push button PBS, and a lead 226 is connected to the lead 225 and to the control lead CS2 and incorporates a third normally open set of contacts PBS" of the emeroif-on switch 228, and the operating coil CC for operating the contacts CS in the circuit of the coolant motor I30. switch P31 is ganged with the switch PB! and the switch PB3..

Switch DR4 on the drum'control switch has one side connected by ,a lead 230 to the control lead1CS2, the lead 230 incorporatinga normally open relay actuated switch BCRI and the latchl-. ingycoil 3CR"ofa relay having associated therewith' anormally closed switch3CRl and a normally open switch 3CR'2. Another lead 23! connects a latching coil CR directly in parallel with the coil 30R. The coil 5CR operates a control relay having associated therewith a normally closed switch ECRI and a normally open switch 5CR2. The other side of the switch DR4 is connected by a lead 232 to one side of a cycle auto-r manual" switch CAM, the other side of this switch being "connected .to "the lead 220.

A branch lead 233 is connected atone end to the lead230intermediate the switches DB4 and HCRI and at the other end to the control lead CS2. the lead 233 incorporating a normally open relay actuated switchfiCRl and the latching coil I CR 01' a relay having associated therewith a normally close'd'switch' ICRI and a normally open switch t- A parallel branch lead 234 similarly is v ICR2. connected between the leads 23ll and CS2 and incorporates a normally open relay actuated switch ICR2 and the latching .coil 2GB of a relay having a normally closed switch ZCRI and a normally open switch 2CR2; Another lead 235 is connected at one end to the lead 233 intermediate the switch BCRI and the coil ICE and is connected at the "other end to the control lead CS2, said lead 235 incorporating a pair of normally closed contacts of the cycle selecting switch CYS and the latchingcoil 4GB of a relay having associated therewith a normally closed switch 4GB] and a normally open switch 4CR2. The switch'CYS has a pair of normally open contacts whichiare incorporated in a lead'236one end of which is connected to the lead 234 intermediate the switch 'ICR2 and the coil R and the other end of which is connected to the lead 235 intermediate the cycle switch CYS and the coil 40Rv Alead 240 is connected betweenthe lead 220 and the control lead CS2 and incorporates the normally open limit switch ILS which is mounted onthe front cross slide of the machine, and the operating coil, 60R of a relay having one normally open switch BCRI associated therewith, said switch being in the lead 233 in series with the latching coil ICR as earlier described. A first cycle indication lamp MI is connected in parallelwith the coil 60R and is 'illuminated whenever said coil is energized. A lead 242 is connectedat one endto the lead 240 intermediate the limit switch ILS and. the coil 60R, and at the other end to the control lead CS2 and incorporates the release coil R.

A lead 243 is connected between the leads 220 and CS2 in parallel with the lead 240 and incorporates the second limit switch 2LS and the operating coil 1GB of a relay having two normally openswitches 10R] and 10122 associated there- As seen in Fig. 4 the with, the switch 'ICR2 being in the lead 234 in" series with the latching coil 2CR. earlier -described. A second cycle lamp 244 is connected i across the coil TCR and is illuminated whenever said coil is energized, and a lead 245 extends from the lead 243 intermediate the limit switch-2L5 and the coil ICE and connects'to the control lead 2-CS.- The lead 245 incorporates a normally open pair of contacts CYS of the cycle switch CYS and the release coil ICR';

Another circuit generally parallel with the leads 240 and 243 comprises a lead 246 connected between the lead 220 and the control lead CS2 and incorporating the third limit switch 3LSandan operating coil 8GB of a relayhaving, two. normally open switches BCRI' and8CR2 associated therewith, the firstof theseobeing inithe lead V 230 in series with the latching coil 3CR.- A third cycle lamp 241 is connected across the coil R and is illuminated whenever this coil .issener- The release coil 2CR is connected in" gized. parallel with the coil 86R by means of a lead 248, and a lead 249 is connected between the leads 245 and 246 and incorporates two nor-' mally closed contacts of the cycle switch CYSl.

The limit switch 4L8 which is carried on-the rear cross slide of the machine is connected in a lead 250, one end of which is connected to the control lead CS2 and which incorporates the operating coil 9CR of a relay having a single normally open switch SCRI. A branch lead 251 extends from the lead 250 intermediate the limit switch 4L5 and the coil BCR to the control lead CS2 and connects the release coil 5CR in parallel with the operating coil SCR. A circuit parallel to that just described comprises a lead 252 which extends from the fifth limit switch 5L8 to the control lead CS2 and which incorporates the, operating coil IGCR of a relay having a single normally open switch IOCRI associated there with. The release coil- 40R. is connected in parallel with the coil IOCR by means :of a lead 253.

Another lead 254 extends from the lead 232 adjacentthe switch CAM to the control lead CS2 and has incorporated therein. in series the normally closed relay switches ICRI, ZCRI, GCRI, 4GB! and 5CRI the normally open relay switches 'ICRI and SCRI; the normally closed relay switch I4CR2; and theoperating coil HCR of a relay having the two normally open switches HCRI and HCRZ associated therewith, the first of. these being connected across the cycle, start pushbutton contactsv PB! and the secondbeing connected across the cycle start pushhbutton.w

contacts PB l Alead 254a connects the switches 8CR2 and IOCRl .in parallelwiththe "switches.

tioned coil controlling the contacts FSA in the front slide motor circuit and having a normally closed switch FSAI and a normally open switch FSAZ associated therewith. As shown inFig. 5 the point of connection of the leads 250 and 252 with the lead 255 is between the switches GLS and ICR2. The limit switch GLS is closed when the lathe has completed a cycle and is ready forloading.

The normally open' switch 2CR2 is connected around the switch ICR2 by means of a lead 251 and another lead 258 is also in parallel with the switch ICR2 and incorporates the movable contact IPSa and one stationary contact iPSb of a single pole, double throw plugging switch IPS for the front slide motor. The other contact lPSc of this switch is connected by a lead 259 to another lead 260 which is generally parallel with the lead 255 and extends from the lead 255 at its juncture with lead 255a to the control lead CS2. The lead 260 incorporates in series the normally open switch 3CR2, the normally closed switch FSAI, and the actuating coil FSRC for the contacts FSR which are utilized to obtain reverse operation of the front slide motor 96. This relay also has associated therewith the normally closed switch FSRI in the lead 255 and the normally open switch FSR2. Another lead generally parallel with the leads 255 and 260 is designated at 26! and includes the normally open switch 4CR2, a normally closed relay actuated switch RSRE, and the actuating coil RSAC which controls the contacts RSA in the rear slide motor circuit, this relay also having a normally closed switch RSA! and a normally open switch RSAZ.

A lead 262 is connected around the switch 4CR2 and incorporates the movable contact ZPSa and one stationary contact ZPSb of a second plugging switch 2PS for the rear slide motor,

this plugging switch being a single pole double throw switch similar to IPS and having its other stationary contact 2PSc connected by a lead 263 to a lead 264 which is generally parallel to the leads 255, 260 and 26l and which incorporates the normally open switch 5CR2, the normally closed switch RSA! and the actuating coil RSRC for the contacts RSR utilized to obtain reverse operation of the rear slide motor. The coil RSRC also controls the normally closed switch RSRI in the lead 26l and a normally open switch RSR2.

Another lead generally parallel with the lead 284 is designated at 255 and incorporates the switch FSAZ and a safety latch coil lLC for the plugging switch IPS. The switch FSR2 is connected in parallel with the switch FSAZ by means of a lead 256. Another safety latch coil 2LC for the plugging switch 2P8 is connected in parallel with the coil ILC by means of a lead 261 which incorporates the switch RSAZ and said coil 2LC, and the switch RSR-Z is connected in parallel with said switch RSA2 by means of a lead 268.

OPERATION Automatic three out cycZeFirst out To tart the cycle after the cycle switch CYS has been moved from its two out position as shown to its three out position, the run push button MI is closed to energize the coil I5CR, this circuit being readily traceable through the lead 2H1. Energization of this relay coil causes closure of its associated switches iECRI, I5CR2 and I5CR3. Closure of switch I5CR3 starts the spindle motor 30 through the reduced voltage starting arrangement including the transformer T5 in the manner earlier described. After a predetermined lapse of time the timer motor TM operates the timer, causing timer switches TR2 and TR3 to close and switch TRl to open, breaking the reduced voltage starting circuit and connecting the spindle motor 39 directly to the supply line through the contacts MR, this operation having also been earlier described.

The closed switch I5CRI completes the holding circuit around the run button Mi, and the closed switch I5CR2 completes a circuit through the normally closed clamp button M3 to switches DR! and DB5 of the drum control switch. The drum control switch 330 has been shifted by dogs on the controller disc 68 to its rapid approach position wherein, as earlier explained, switches DRE, DB2 and DR5 are closed; and limit switch EELS has been closed by another dog in the machine when the lathe has completed a cycle of operation on a work piece and is ready for loading another work piece. Coil I 3GB. is energized through the closed switch DRZ. As the machine starts operation limit switch ILS on the front cross slide will be closed by the mechanism shown in Fig. 1, thus completing a circuit to energize coil SCR (thereby closing normally open contacts 60R!) and to energize the unlatching coil 30R, thus leaving contacts 3GB! closed and 3CR2 open. These circuits may be traced as follows: control lead CSI, run switch MI (and its parallel holding circuit), lead 220 and lead 240 incorporating switch ILS and coil SCR. The unlatching coil 30R is connected in parallel with the coil 60R by the lead 242.

The limit switch lLS on the rear cross slide will be closed by the actuating member on the mechanism shown on Fig. l to energize coil HCR and unlatching coil 50R. These circuits may be traced as follows: control lead CS1 to lead 229 as earlier described, lead 255 through limit switch 6L8, lead 255a, and lead 253 through limit switch ALS and coil R, the unlatching coil 5CR' being connected in parallel with the coil 90R. Closure of this circuit closes the normally open switch SCRI and places the normally open switch 5CR2 in open position and the normally closed switch 5CRI in closed position.

With the circuits in this condition, closing the cycle start push button P will energize coil RAC of the rapid approach starter, this circuit being traced from lead CS! through lead 2H3, all the switches in lead 255 now being closed. Energization of the coil RAG causes contacts BA to close to start the rapid traverse motor 632 in the rapid approach direction. A holding switch HA2 is simultaneously closed to maintain the circuit through the coil RAG, this last mentioned switch being in parallel with the push button PBi. Push button PBi has a mechanical connection with push button PEI which simultaneously closes to energize coil lECR, this circuit bein from CS! through lead 2 E4 and lead 223 incorporating drum switch DB5 and a series of closed push button switches. When the coil iZCR is energized a holding circuit around the push button PE! is established through the now closed switch IZCR- l. Closing the switch it' -32f? energizes the spindle clutch solen id through a circ t earlier described, and opening the switch iZCRl deenergizes the spindle brake release solenoid BRE through a circuit earlier described so that the brake is released, while closure of switch 12CR3 causes the unlatching coil l liCR' to be energized. The rapid approach movement of the tools then continues until dog 33 throws the drum switch into its feed position wherein switches DRI, DRE, CR3 and are open and the left side (in Fig. 4) of switch is closed.

Opening of switch DR! stops the rapid traverse motor by breaking the circuit to thecoil RAC so that contacts RA open and switch RAI 15 closes :to energize the .brake solenoid .BRI. Opening of drum switch DB2 deenergizes coil 130R, thereby opening the switch I3CR in the lead '21-! and closing the switch 53CR2 in the lead 224.

The spindle motor 36 then continues to operateto drive'the spindle and the tools continue to move'at a feed rate until dog 335 operatesthe drum switch and moves it to rapid return pos1- ticn wherein switches DPtl, DR? and DRE are open andtswitches DB3 and DB4 are closed.

Theopening of switch DB5 breaks the lead 223 and deenergizes relay coil IZCR to disengage the spindle clutch by opening the switch l2CR2, and to set the spindle brake by closing the switch IZCRE. Closing of drum switch DB3 energizes coil RRC through lead 222, thereby closing contacts .RRLto operate the rapid traversemotor 62 inits return direction and opening switch HR! to release the traverse motor brake. Closing of drum switch contacts BRA completes a circuit between leads 23s) and 232 and energizes the latching coil iCR through the lead 233 which incorporates the still closed switch fiCRl. When the relay ECR is energized the switch lCRI is opened and the switch ECRZ is closed. The rapid return movement of the tool'slide continues until a dog shifts the drum switch'back to its rapid approach position and another dog simultaneously closes the limit switch GLS. In its rapid approach position switches DRI, DRE and DRE: are closed while switches DB3 and D34 are opened, and the opening of switch DB3 deenergizss coil and drops out contacts RR to stop the 1' d motor. However, the cycle will not resuine until the front slide is advanced or adjusted for the second depth of cut and coils BAG and EZCR are again energized.

First front slide adjustment W'ith switch BLS closed and the control relay having the coil ICE in latched position, the coil FSAC of the front slide advance relay is energized, this circuit extending from lead CS! through lead 213 to lead 229 and through lead 255 incorporating the closed switches ELS and ICR2. Energization of the coil F-SAC causes switch FSAI to open and switch FSAE to close, and additionally closes contacts FSA to start the front slide motor in its advance direction. The front slide continues to advance until the members I05 on the control mechanism open limit switch ILS'and close limit switch 211s, this latter action completing a circuit through lead 243'to energize'the coil 'iCR so that switches 'ICRI and 'ECRZ close, while the opening of the limit switch iLS breaks the lead 240 and causes the coil 60R to drop out, thereby opening switch BCRI in lead 233 so that coil lCR, becomes deenergized.

The front slide motor is then stopped by "plugging or temporarily connecting the motor to the supply line for reverse rotation by means including the plugging switch 1P8. For safety reasons this plugging switch has the latch coil ILC which prevents either contact on the plugging switch from closing until the latch coil is energized. When the coil FSAC was energized contacts FSA2 were closed as above noted to energize the latch coil ILC, thereby closin the plugging switch contacts lPSa and, I PS0 to complete a circuit between the leads 258 and 256 and energize coil FSRC, which closes contacts FSR. When the motor 86 slows down and just prior 16 to reversing, the plugging switch .IPS is designed (as by a centrifugalgovernor) to open to break contact between leads 258 andlfifian'd deenergize the coil FSRC, thereby opening contacts FSH and allowing the motor to stop.

Second rapid approach The control release apparatus having operating coils ZCR, 30R, 40R and 5GB have been in their released positions so far during the cycle of the machine. The relay coil 90R is energized and the switch SCRI is closed due to the rear slide closing the limit switch 4L8 with the result that the normally open switch QCRI in the lead 254 is closed. When the front slide has advanced to its second cut position and deenergized the relay coil lCRiand energized the relay coil'lCR, relay coil HCR is energized, the lead 254 .now being completely closed with the switch ICRI in its normal closed position and the switch 'ICRI closed due to the energization of thecoil ICR. Consequently switches IICRI and CR2 are closed. Closing the switch IICRI shorts around push button PBI to energize coil RAG, and closing of switch I ICRZ shorts around push button PEI, energizing coil IZCR so that the tool slides again move through rapid approach and rapid return positions of their cycle in the same manner as previously described.

Second rapid return Since the limit switch 2LS on the front slide closed to energize the coil 10R whenthe drum switch is thrown into its rapid return position wherein switches DR3 and DB4 are closed, the latch coils 20R and 40R are energized, the circuit for latch coil ZCR. extending from control lead CSI through lead 2|3, lead 220, switch CAM, lead 232, switch DR4, lead 230, and lead 234 incorporating the now closed switch 'ICRZ. The circuit for the latch coil 401% is partially common with that for the coil 20R and includes the lead 236 which branches from the lead 234 beyond the switch ICRZ. As a result of the energization of these two coils, switches 2CRl2 and 4CR2 are closed and switches 20R! and ACRI are opened. The opening of the last mentioned switches breaks the circuit to the coil IICR, the closing of switch 2CR2 completes the circuit through lead 251 to the coil FSAC, and the closing of switch 4CR2 conditions the circuit of the czzoill RSAC, since the switch 4CR2 is in the lead Second front slide adjustment When the limit switch BLS is again closed at the end of the rapid return movement of the front slide, switch 2CR2 energizes coil FSAC to close the front slide motor contacts FSA and cause the front slide to advance towards its third cutting position until the limit switch 3L8 on the front slide closes to energize the release coil ZCR' (thus opening contacts ZCRZ and closing contacts 2 CR!) and to energize coil R which is in parallel with the release coil 20R. Energization of the coil 80R closes normally open contacts BCRI and BCEZ. The motoris stopped .by plugging as earlier described.

Rear slide adjustment The closing of contacts 'ICRZ in lead 234 energized coil 40R, thereby closing the normally open contacts dCRZ and energizing the rear slideladvance coil RSAC and closing contacts RSA to start the rear slide motor I I8. The rear slide advances until it closes limit switch 5L8 andthereby energizes coil 19GB and the release coll 4GB.

which is in parallel therewith. The motor l 28 is,

stopped by plugging through the switch ZPS as earlier described in connection with the switch UPS and the motor 35.

Third rapid approach With both slides advanced limit switches 3L8 and 5L8 are closed to energize coils tCR and MGR, release coils 26R and 40B being in parallel and being energized simultaneously. As a consequence of this action coil IICR is energized. through lead v254 and the parallel lead 254a incorporating the now closed switches 803.2 and IcCRI. Energization of the coil HCR. closes a circuit around the push button PBI, resulting in energization of the coil RAG with closure or" the contacts RA and operation of the rapid motor 62 in advance direction, together with operation of the spindle motor in the same manner as earlier described.

Both slides return With coil "80R energized the switch SCR-i in the lead 238 is closed and coils 30R and 50R will latch during the last rapid return. Then when limit switch tLS is closed the coil F330 is energized through the closed switch SCRZ to return a the front slide and the coil RSRC is energized through the now closed switch fiCRE'to return the rear slide. When the front slide returns to close limit switch ILS it energizes the release coil 3ClFl.,-opening the switch BCRZ and dropping out the coil FSRC. In the meanwhile, the plugging switch iPS has operated in the reverse direction than that earlier described to complete the lead 253 so when the coil FSRC drops out switch FSRI closes and the motor tends to reverse until it slows down enough to allow the plugging switch to open. This drops out the coil FSAC and the motor stops. The rear slide plug stops the motor E H3 in the same manner after closing limit switch lLS which energizes release coil R. Opening of the switches in the lead 254 causes the coil ICE to become deenergized, both of the parallel switches lCRl and 801332 being open. Consequently, the cycle cannot start again until the cycle start button is again pressed.

Automatic two out cycle When it is desired to run the machine through cycle of only two cuts the cycle switch CYS is closed its cycle two position which eliminates the second position on the front slide. During rapid return after the first cut coils l6? and SCR are both latched, being connected in parallel by means of cycle switch when said switch is in its out position as shovm. The'switches asso ciated with the coil iCR. allow thefront slide to advance until limit switch ails'cmses the circuit normally open. Upon operationof the push but ten the contacts P35 break the" circuit to the coil 18 RAG to stop rapid approach, and the contacts PBS break the circuit to the coil WCR to disengage the clutch and brake the spindle motor to stop. When the drum switch is in rapid approach position the switch DRE is closed and the coil lI'lCR is energized through the lead 22L In any other position of the switch the relay I3CR is deenergized and the switch i3CR2 is closed. The contacts P35 act to complete a circuit to energize relay coil MGR, and the switch MCRI cause energization of the coil REC for rapid return whenever switch EECR? is closed, while the switch MCRZ opens to insure that the coil I ICE is not energized. so that the cycle may not start again. With the apparatus in this condition the relay coil MGR is energized through the switch EECRS at the beginning of the next cycle to unlatch the relay.

if the emergency button is used during rapid approach while switch NOR?! is open the relay MCB- will not be latched since the lead 224 is open, butv the machine will stop. In this case the work can be unclamped and. removed and the machine allowed to complete its cycle, or the means of the lead 2 i6, and the log return and jog spindle buttons break the circuit to the coil EECR to stop the spindle.

cuit around the switch MGR! to energize the coil REC; and the other pair PB? on the jog spindle button PB? complete a circuit for direct energization of the coil EZRC.

Cycle aut0-mcmua2 switch When the cycle automanual switch CAM is in the manual or open position the circuit to the coil HCR is open and consequently the rapid approach motor cannot be energized. With the button in this position after the tools advance each cut must be started by pressing the cycle start button PBi since there is no holding circuit around this button, the switch i ECRI being open.

We claim: g,

1. In a lathe having a rotatable work supporting spindle, a front carriage reciprocable longitudinally of the spindle axis, a front toolcarrying cross slide adjustable transversely on the front carriage, means .forreciprocating the front carriage and means foractuating the cross slide during movement of the carriage comprising a cam bar extending longitudinally of the carriage and stationary with respect thereto and having a slot with a portion parallel to the spindle axis and a connecting portion extending diagonally outwardlytherefrom, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower operable in said cam slot, and means for adjusting said bar member on said cross slide comprising a reversible electric motor supported on the cross slide and connecting means including a screw and nut device intermediate said. motor and bar member, means ineluding a switch carried on the cross slide operable upon the completion 01 a cutting cycle to The other pair of c0nj tacts on the jog return button PBt complete a cirenergize said motor to adjust said bar member slide with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means operable upon completion of a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools during a third cutting cycle, means including a third switch operable upon completion of said third cutting cycle to return the bar member and cross slide to their original relative position, and braking means for said motors to insure accurate adjusting of said cross slides upon the respective carriages, said braking means comprising means for disconnecting said motors and for simultaneously temporarily reversely connecting said motors, and for breaking the reverse connections before reverse operation of the motors occurs.

2. In a lathe having a rotatable work supporting spindle, a front carriage reciprocable lon itudinally of the spindle axis, a front tool-carrying cross slide adjustable transversely onv the front carriage, means for reciprocating the front carriage and means for actuating, the cross slide during movement of the carriage comprising a Cam bar extending longitudinally of the carriage and stationary with respect thereto and having a slot with a portion parallel to the spindle axis and a connecting portion extending diagonally outwardly therefrom, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower operable in said cam slot, and means for adjusting said bar member on said cross slide comprising a reversible electric motor supported on the cross slide and connecting means including a screw and nut device intermediate said motor and bar member, means including a switch carried on the cross slide operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means operable upon completion of a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools during a third cutting cycle, and means including a third switch operable upon completion of said third cutting cycle to return the bar member and cross slide to their original relative position.

3. In a lathe having a rotatable work supporting spindle, a carriage reciprocable longitudinally of the spindle axis, a tool-carrying cross slide adjustable transversely on the carriage, means for reciprocating the carriage and means for actuating the cross, slide during movement of the carriage comprising a cam bar extending longitudinally of the carriagev and stationary with respect thereto and having. a. slot with. a portion parallel to the spindle. axis and a connecting portion extending diagonally outwardly therefrom, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower operable in said cam slot, and means for adjusting said bar member on said cross slide comprising a reversible electric motor supported on the cross slide and connecting means including a screwand nut device intermediate said motor and bar member, means including a switch carried on the cross slide operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means operable upon completion of a sec ond cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools during a third cutting cycle, and means including a third switch operable upon completion of said third cutting cycle to return the bar member and cross slide to their original relative position, and control means including a circuit having a switch movable between two positions, said circuit controlling the operation of said lathe to omit one of said adjusting operations and cutting cycles when the switch is in one position.

4. In a lathe having a rotatable. work support ing spindle, a front carriage reciprocable longitudinally of the spindle axis, a front tool-carrying cross slide adjustable transversely on the front carriage, means forv reciprocating the front carriage and means for actuating the cross slide during movement of the carriage comprising a cam bar extending longitudinally of the carriage and stationary with respect thereto and having a slot with a portion parallel to the spindle axis and a connecting portion extending at an angle therefrom, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower operable in said cam slot, and means for adjusting said bar member on said cross slide comprising a reversible electric motor supported. on the cross slide and connecting means including a screw and nut device intermediate said motor and bar member, means operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means. operable upon completion of a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools during a third cutting cycle, and means operable upon the completion of said third cutting cycle to return the bar member and cross slide to their original relative position.

5. In a lathe having a rotatable work supporting spindle, a front carriage reciprocable longitudinally of the spindle axis, a front toolcarrying cross slide adjustable transversely on the carriage, mechanism for actuating said carriage and cross slide through a cycle wherein a tool on the cross slide is moved from a withdrawn position towards the spindle axis to a cutting depth and thereafter is moved longitudinally of the spindle axis to perform a turning operation and is then returned to said withdrawn position, means operable after av turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper cut during another cycle of operation, comprising a motor carried, on the cross slide, a bar member slidable relative to the cross slide transversely of the spindle axis, a cam follower on said bar member operable on a stationary cam extending longitudinally of the carriage and gearing intermediate said motor and bar member for adjusting the relative position of the bar and the cross. slide, and means for controlling said motor comprising a, plurality of switch devices carried on said cross slide, a rotatably mounted switch actuating member, and a rack and pinion device between said switch actuating member and bar member.

6. In a lathe having a rotatable work supporting spindle, a front carriage reciprocable longitudinally of the spindle axis, a front toolcarrying cross slide adjustable transversely on the carriage, mechanism for actuating said carriage and cross slide through a plurality of cycles wherein a tool on the cross slide is moved from a withdrawn position towards the spindle axis to a cutting depth and thereafter is moved longitudinally of the spindle axis to perform a turning operation and is then returned to said withdrawn position, means operable after a turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper out during another cycle of operation comprising a motor carried on the cross slide, a bar slidable relative to the cross slide transversely of the spindle axis and gearing intermediate said motor and bar for adjusting the relative position of the bar and the cross slide, a plurality of switches on said cross slide for controlling the operation of said motor, and a switch actuating member rotatable upon relative movement of said bar and cross slide for operating said switches.

7 In a lathe having a rotatable work supporting spindle, a carriage reciprocable longitudinally of the spindle axis, a tool-carying cross slide adjustable transversely on the carriage, means for reciprocating the carriage and means for actuating the cross slide during movement of the carriage comprising a cam member extending longitudinally of the carriage and stationary with respect thereto and having a slot with a portion parallel to the spindle axis and a connecting portion extending diagonally outwardly therefrom, a bar member adjustably supported on said cross for movement transversely of the spindle axis and carrying a follower operable in said cam slot, and means for adjusting said bar member on said cross slide comprising reversible motor means supported on the cross slide and connecting means intermediate said motor and bar, means carried on. the cross slide operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper-cut of the tools during a second cutting cycle, means operable upon completion or a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools durin a third cutting cycle, and means operable upon the completion of said third cutting cycle to return the bar member and cross slide to their original relative position.

8. In a lathe having a rotatable work supporting spindle, carriage reciprccable longitudinally of the spindle axis, a tool-carrying cross slide adjustable transversely on the carriage means for reciprocating the carriage and means for actuating the cross slide during movement of the carriage comprising a cam member having a portion parallel to the spindle axis and a connecting portion extending at an angle therefrom, a bar member adiustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower cooperating with said cam, and means for adjusting said bar memher on said cross slide comprising a reversible electric motor supported on the cross slide and connecting means including a screw and nut device intermediate said motor and bar member, means operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means operable upon completion of a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper cut of the tools during a third cutting cycle,

means operable upon the completion of said third cutting cycle to return the bar member and cross slide to their original relative position, and corn trol means including a circuit having a switch movable between two positions, said circuit controlling the operation of said machine to omit said second cutting cycle when the switch is in one position.

9. In a lathe having a rotatable Work supporting spindle, a carriage reciprocable longitudinah 1y of the spindle axis, a tool-carrying cross slide adjustable transversely on the carriage, means for reciprocating the carriage and means for actuating the cross slide during movement of the carriage comprising a cam member having a por tion parallel to the spindle axis and a connecting portion extending at an angle therefrom, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis and carrying a follower cooperating with said cam, and means for adjusting said bar member on said cross slide comprising a reversible motor on said cross slide and connectin means intermediate said motor and bar member, means operable upon the completion of a cutting cycle to energize said motor to adjust said bar member with respect to said cross slide to effect a deeper cut of the tools during a second cutting cycle, means operable upon completion of a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper out of the tools dur' ing a third cutting cycle, and means operable upon the completion of said third cutting cycle to return the bar member and cross slide to their original relative position.

10. In a lathe havin a rotatable work support ing spindle, a front carriage reciprocable longitudinally of the spindle axis, a front tool-carrying cross slide adjustable transversely on the carriage, mechanism for actuating said carriage and cross slide through a cycle wherein a tool on the cross slide is moved from a withdrawn position towards the spindle axis to a cutting depth and thereafter is moved longitudinally of the spindle axis to perform a turning operation and is then returned to said withdrawn position, means operable after a turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper cut during another cycle of operation comprising a motor carried on the cross slide, a member siidable relative to the cross slide tranversely of the spindle axis and forming a part of said actuating mechanism and operable to move the cross slide to cutting depth and connecting means intermediate said motor and memher for adjusting the relative position of the memher and the cross slide, and means for controlling said motor comprising a plurality of switches carried on said cross slide and operable upon relative movement of said member and cross slide.

11. In a lathe having a work supporting spindle rotatable about an axis, a carriage reciprocable longitudinally of said axis, a tool-carrying cross slide adjustable on the carriage transversely of said axis, means for moving said carriage and cross slide longitudinally of the spindle axis to cause a tool on the cross slide to perform a turning operation and for returning said carriage and cross slide to complete a cutting cycle, a bar member adjustably supported on said cross slide for movement transversely of the spindle axis, and means for adjusting said bar member on said cross slide comprising a motor supported on the cross slide and gearing including a screw and nut device intermediate said motor and bar member,

means operable upon the completion oi a cutting cycle to energize said motor to adjust bar member with respect to said cross slide to effect do :1- out of the tools during a second cutting cycle, means operable upon completion oi a second cutting cycle to energize said motor to adjust the bar member again to effect a still deeper out of the tools during a third cutting cycle, and means operable upon the completion of said third cutting cycle to return the bar member and cross slide to their original relative position.

In a machine tool having a Work supporting spindle rotatable about an axis, a carriage recip cable longitudinally of said axis, a tool-carrying cross slide adjustable on the carriage transversely of said axis, means for moving said carriage and cross slide longitudinally of the spindle axis to cause a tool on the cross slide to perform a turning operation and for returning car 'iage and cross slide to complete a cutting cycle, means for adjusting said cross slide transversely on said carriage comprising reversible motor means, means operable upon the completion of a cutting cycle to energize said motor to adjust said cross slide to cifect a deeper out of the tools during a second cutting cycle, means operable upon completion of a second cuttin cycle to energize said motor to adjust said cross slide again to effect still deeper out of the tools during a third cutting cycle, means operable upon the completion of said third. cutting cycle to return the cross slide to its original position, and control means including switch means for controlling the operation of said machine selectively to omit said second cutting cycle.

13. in a machine tool having a Work supporting spindle rotatable about an axis, a carriage adjustable longitudinally of said axis, a tool-carrycross slide on the carriage movable trans-- versely of said means for actuating said carriage and cross slide through a cycle wherein a tool on the cross slide is moved longitudinally of the spindle axis to perform a turning' operation, means operable after a turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper cut during another cycle of operation comprising motor means on the cross slide, a bar movable relative to the cross slide transversely of the spindle axis and comiectingmeans including gearing and a screw and nut device intermediate said motor means and bar for adjusting the position or the bar on. the cross slide, means for controlling said motor means comprising a plurality of control members carried on said cross slide and operable upon relative movement of said bar and cross slide, and control means including switch means for controlling the operation of said actuating means through a selected predetermined number of cycles.

14. a lathe having a work supporting spindle rotatable about an axis, a carriage reciprocablc lon *itudinally of said axis, a tool-carrying cross slide on the carriage adjustable transversely of axis, means for actuating said carriage and cross slide through a cycle wherein a tool on the cross slide is moved longitudinally of the spindle axis to perform a turning operation and is then returned, means operable after a turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper out during another cycle of operation comprising reversible motor means on the cross slide, a bar slidable relative to the cross slide transversely of the spindle axis and connecting gearin inter- -li.ate said motor and bar for adjusting the position of the bar on tl cross slide, and means for controlling said motor comprising a plurality of control members carried on said cross slide and at least one actuating member operable on said control members in response to relative movement of said bar and cross slide.

15. In a machine tool having a Work supporting spindle rotatable about an axis, a carriage movable longitudinally of said axis, a tool-carrying cross slide adjustable on the carriage transversely of said axis, means for actuating said carriage and cross slide through a cycle wherein a tool on the cross slide is moved longitudinally of the spindle axis to perform a turning operation, and means operable after a turning operation to adjust the cross slide transversely of the spindle axis to cause the tool to take a deeper cut during another cycle of operation comprising motor means on the cross slide, a bar movable relative to the cross slide transversely of the spindle axis and connecting means including gearing and a screw device intermediate said motor means and bar for adjusting the position of the bar on the cross slide, and means for controlling said motor means comp-rising a plurality of control members carried on said cross slide and operable upon relative movement of said bar and cross slide.

TIMOTHY B. BUELL. HARRY R. LEBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Lil-6755s Carson Feb. 1, 1921 2,092,933 Buell May 28, 1935 2,105,744 Le Tourneau Jan. 18, 1938 2,134,024 Bogart Oct. 25, 1938 2,144,735 G-ranberg Jan. 24, 1939 2,172,999 Hoelscher Sept. 12, 1939 2,351,649 wintermutepmflufl June 20, 1944 2,389,368 King Nov. 20, 1945 2,450,696 Siekmann Sept. 28, 1948 

